The present invention is concerned with antibacterial 4"-epi-9-deoxo-9a-methyl-9a-aza-9a-homoerythromycin A, pharmaceutically-acceptable salts thereof, and intermediates useful in the preparation thereof from erythromycin A.
Erythromycin A is a well-known macrolide antibiotic, having the formula (I), which has found extensive clinical use. ##STR1##
The present therapeutic compcund is the 4"-epimer of the previously reported erythromycin A derivative of the formula (II), the ##STR2##
(II) R=methyl
(III) R=hydrogen
subject of Belgian Pat. No. 892,357, as well as of my co-pending U.S. application, Ser. No. 399,401, filed July 19, 1982, now abandoned. In that Belgian patent, the compound of the formula (II) is named as the N-methyl derivative of "11-aza-10-deoxo-10-dihydroerythromycin A", a name coined earlier by Kobrehel et al., U.S. Pat. No. 4,328,334 for the precursor compound of the formula (III). For the latter ring expanded (homo), aza (nitrogen substituted for carbon) erythromycin A derivative, we prefer the name 9-deoxo-9a-aza-9a-homoerythromycin A. That compound could also be named as a 10-aza-14-hexadecanolide derivative.
Certain of the present novel intermediates are likewise 4"-epimers of previously known compounds. Thus 4"-epi-9-deoxo-9a-aza-9a-homoerythromycin A is the 4"-epimer of the above compound of the formula (III); and 4"-epi-erythromycin A oxime is the 4"-epimer of the erythromycin A oxime of Djokic et al., U.S. Pat. No. 3,478,014. 4"-Epi-erythromycin A is the subject of co-pending U.S. patent application, Ser. No. 353,547, filed Mar. 1, 1982 by Sciavolino et al, now U.S. Pat. No. 4,382,085.